Anti-tubercular agents. Part 8: Synthesis,antibacterial and antitubercular activity of 5-nitrofuran based 1,2,3-triazoles

A series of 5-nitrofuran–triazole conjugates were synthesized and evaluated for their antimicrobial activity against both Gram-positive and Gram-negative bacterial strains. All the compounds exhibited promising inhibition towards Gram-positive pathogenic strains, while mild inhibitory effects were observed towards Gram-negative bacterial strains. Some of the compounds 8a, 8b, 8e, 8f, 8h are most active among the series exhibiting MIC value of 1.17 μg/ml against different bacterial strains. The bactericidal activity is found to be in accordance with the bacterial growth inhibition data. Compound 8e was found to be equipotent to the standard drug Ciprofloxacin displaying MBC value of 1.17 μg/ml against the bacterial strain Bacillus subtilis. The compounds have also demonstrated promising antibacterial activity against the resistant strain MRSA and were found to be effective inhibitors of biofilm formation. The compound 8b exhibited excellent anti-biofilm activity with IC₅₀ value as low as 0.8 μg/ml. These conjugates were also screened for antitubercular activity against Mycobacterium tuberculosis H₃₇Rv strain. Compound 8e showed promising antitubercular activity with MIC value of 0.25 μg/ml. Most of these compounds are less toxic to normal mammalian cells than the widely used antibacterial drug Ciprofloxacin.     

Comparative study of antifungal activity of two preparations of green silver nanoparticles from Portulaca oleracea extract

The green silver nanoparticles (green AgNPs) exhibit an exceptional antimicrobial property against different microbes, including bacteria and fungi. The current study aimed to compare the antifungal activities of both the crude aqueous extract of Portulaca oleracea or different preparations of green AgNPs biosynthesized by mixing that aqueous extract with silver nitrate (AgNO₃). Two preparations of the green AgNPs were synthesized either by mixing the aqueous extract of P. oleracea with silver nitrate (AgNO₃) (normal AgNPs) or either irradiation of the AgNPs, previously prepared, under ⁶⁰Co γ-ray using chitosan (gamma-irradiated AgNPs). Characterization of different AgNPs were tested by Zeta potential analyzer, Ultraviolet (UV) Visible Spectroscopy, and Fourier-Transform Infrared (FTIR) spectrometry. Three different plant pathogenic fungi were tested, Curvularia spicifera, Macrophomina phaseolina, and Bipolaris sp. The antifungal activities were evaluated by Transmission Electron Microscope (TEM) for either the crude aqueous extract of P. oleracea at three doses (25%, 50%, and 100%) or the newly biosynthesized AgNPs, normal or gamma-irradiated. With a few exceptions, the comparative analysis revealed that the irradiated green AgNPs at all three concentrations showed a relatively stronger antifungal effect than the normal AgNPs against all the three selected fungal strains. UV–visible spectroscopy of both preparations showed surface plasmon resonance at 421 nm. TEM results showed that both AgNPs were aggregated and characterized by a unique spherical shape, however, the gamma-irradiated AgNPs were smaller than the non-irradiated AgNPs (0.007–0.026 µM vs. 0.009–0.086 µM). TEM photographs of the fungal strains treated with the two AgNPs preparations showed flaccid structures, condensed hyphae, and shrunken surface compared with control cells. The data suggested that the biosynthesized P. oleracea AgNPs have antifungal properties against C. spicifera, M. phaseolina, and Bipolaris sp. These AgNPs may be considered a fungicide to protect different plants against phytopathogenic fungi.     

Molecular cloning and expression of ranalexin, a bioactive antimicrobial peptide from Rana catesbeiana in Escherichia coli and assessments of its biological activities

The coding sequence, which corresponds to the mature antimicrobial peptide ranalexin from the frog Rana catesbeiana, was chemically synthesized with preferred codons for expression in Escherichia coli. It was cloned into the vector pET32c (+) to express a thioredoxin-ranalexin fusion protein which was produced in soluble form in E. coli BL21 (DE3) induced under optimized conditions. After two purification steps through affinity chromatography, about 1 mg of the recombinant ranalexin was obtained from 1 L of culture. Mass spectrometrical analysis of the purified recombinant ranalexin demonstrated its identity with ranalexin. The purified recombinant ranalexin is biologically active. It showed antibacterial activities similar to those of the native peptide against Staphylococcus aureus, Streptococcus pyogenes, E. coli, and multidrug-resistant strains of S. aureus with minimum inhibitory concentration values between 8 and 128 μg/ml. The recombinant ranalexin is also cytotoxic in HeLa and COS7 human cancer cells (IC₅₀?=?13–15 μg/ml).     

Antibacterial effect and proteomic analysis of graphene-based silver nanoparticles on a pathogenic bacterium Pseudomonas aeruginosa

Graphene-based silver nanoparticles (Ag NPs–GE) material has been developed and demonstrated antibacterial effect against Escherichia coli and Pseudomonas aeruginosa. In this study, the antibacterial activity and mechanism on P. aeruginosa were investigated. The experiments results showed the minimum bactericidal concentration of Ag NPs–GE to P. aeruginosa is 20 μg/ml. When P. aeruginosa were exposed to 20 μg/ml Ag NPs–GE for 1 h, the cell wall was breakdown. In order to study the mechanism of antibacterial effect of Ag NPs–GE, two-dimensional electrophoresis was carried out to compare the protein expressional profiles of P. aeruginosa exposed to 5 μg/ml Ag NPs–GE or 5 μg/ml AgNO₃ with the untreated bacteria. Identification of differentially expressed protein was performed by MALDI–TOF/TOF MS. The change of proteomic profile induced by Ag NPs–GE was distinct from that induced by AgNO₃. Seven identified proteins were found induced and nine proteins were suppressed by Ag NPs–GE. Five identified proteins were found induced and twenty proteins were suppressed by AgNO₃. In addition, either Ag NPs–GE or AgNO₃ suppressed the expression of eight proteins, amidotransferase, 30S ribosomal protein S6, bifunctional proline dehydrogenase/pyrroline-5-carboxylate dehydrogenase, arginyl-tRNA synthetase, nitroreductase, acetolactate synthase 3, methionyl-tRNA synthetase and periplasmic tail-specific protease. Furthermore, gene ontology analysis and KEGG pathway analysis were used to characterize the functions of those proteins.     

Antimicrobial activity of Araucaria cunninghamii Sweet and the chemical constituents of its twigs and leaves

The present study was aimed at the identification of antimicrobial components from Araucaria cunninghamii with an activity-guided purification process. Eight compounds were obtained from the most active n-BuOH fraction and identified as the new compound 4-n-butoxyl-phenylpropanetriol (1), together with seven known compounds (2–8). These compounds were tested for antimicrobial activities against five bacteria and four plant pathogenic fungi. Within the series of compounds tested, compound 2 was the most active, particularly displaying moderate antibacterial activities against Erwinia carotovora and Bacillus subtilis with MICs 7.8 and 15.5 μg/ml. Moreover, this compound exhibited inhibitory activities against four plant pathogenic fungi: Helminthosporium sativum, Rhizoctonia solani, Fusarium oxysporum f. sp. Niveum and Fusarium oxysporum f. sp. Cubense, with EC₅₀ values of 42.3, 90.0, 62.7 and 100.2 μg/ml. To our knowledge, this is the first report that the n-BuOH fraction and compound 2 from A. cunninghamii showed inhibitory activity against plant pathogenic fungi.     

Combined in vitro and in silico approach to evaluate the inhibitory potential of an underutilized allium vegetable and its pharmacologically active compounds on multidrug resistant Candida species

Candida infections and related mortality have become a challenge to global health. Nontoxic and natural bioactive compounds from plants are regarded as promising candidates to inhibit these multidrug resistant strains. In the present study, in vitro assays and in silico molecular docking approach was combined to evaluate the inhibitory effect of crude extracts from Allium ampeloprasum and its variety A. porrum on Candida pathogens. Phytochemical screening revealed the presence of phenolic acids and flavonoids in higher quantity. Spectral studies of the extracts support the presence of phenols, flavonoids and organosulfur compounds. Aqueous extract of A. ampeloprasum showed a total antioxidant capacity of 68 ± 1.7 mg AAE/ g and an IC₅₀ value of 0.88 ± 2.1 mg/ml was obtained for DPPH radicals scavenging assay. C. albicans were highly susceptible (19.9 ± 1.1 mm) when treated with aqueous A. ampeloprasum extract. Minimum inhibitory concentrations were within the range of 19–40 μg/ml and the results were significant (p ≤ 0.05). In silico molecular docking studies demonstrated that bioactive phytocompounds of A. ampeloprasum and A. porrum efficiently interacted with the active site of Secreted aspartyl proteinase 2 enzyme that is responsible for the virulence of pathogenic yeasts. Rosmarinic acid and Myricetin exhibited low binding energies and higher number of hydrogen bond interactions with the protein target. Thus the study concludes that A. ampeloprasum and A. porrum that remain as underutilized vegetables in the Allium genus are potential anti-candida agents and their pharmacologically active compounds must be considered as competent candidates for drug discovery.     

Phytochemical characterization,antioxidant activity,and in vitro investigation of antimicrobial potential of Dittrichia viscosa L. leaf extracts against nosocomial infections

Dittrichia viscosa L., is a perennial plant belonging to the Asteraceae family, and this study was performed to investigate the chemical composition of its extract, using gas chromatography–mass spectrometry (GC–MS). Total phenol (TPC), flavonoid (TFC), and tannins contents (TTC), were quantified using colorimetric methods in two extracts (EtOH and ACE). The antioxidant activity was evaluated using DPPH scavenging, phosphomolebdenum test (TAC) and ferric reducing power assay (FRAP). The antimicrobial activity was determined against six nosocomial pathogens: Bacillus subtilis, Staphylococcus aureus, Salmonella enterica, Escherichia coli, Candida albicans, Aspergillus niger, using disc diffusion method and microdilution assay. The ACE and EtOH extracts had similar TPC: 151.18 ± 1.57 and 127.09 ± 15,81 mg GAE/ g DW. TFC & TTC recorded were also closely matched. The chemical composition revealed the presence of 18 phytochemical compounds with a total of 99.91%, where trimethylsilyl-meso-inositol (20.54%) was the major compound, followed by 5(4H)-Thebenidinone (16.80%). Both extracts showed high radical scavenging activity with an IC₅₀ equal to 12.54 ± 0.2 μg/mL for EtOH, and 7.84 ± 0.1 μg/mL for ACE in DPPH test. In the FRAP test, we recorded an EC₅₀ of 6.37 ± 0,012 mg/mL for EtOH, and 6 ± 0.022 mg/mL for ACE. The ACE presented higher antioxidant capacity (253.52 ± 2.98 mg AAE/g) compared to EtOH (189.14 ± 4,86 mg AAE/g) in the TAC assay. The higher inhibition zone was observed on B. subtilus (13 ± 0.1 mm) for EtOH, and the ACE was more effective on S. enterica (13.3 ± 0.08 mm). All the microbial strains were sensitive for both extracts, with MICs ranging from 0.93 mg/mL to 15 mg/mL.     

Phytochemical profiling,antioxidant and antibacterial efficacy of a native Himalayan Fern: Woodwardia unigemmata (Makino) Nakai

Present work elucidates the antioxidant and antibacterial activity of Woodwardia unigemmata (Makino) Nakai along with chemical characterization using its aqueous (AEW), methanol (MEW), and hexane (HEW) extracts. Chemical profile of different extracts was illustrated by using Gas chromatography and mass spectrometry (GC-MS) analysis. Antioxidant activities were tested using DPPH and FRAP assays, total phenolic and flavonoid content by Folin-Ciocalteu and aluminum chloride method, respectively. Further, antibacterial activity against six plant and four animal pathogenic bacteria was analyzed by employing the disc diffusion assay. GC-MS analysis revealed the presence of catechol (21.96%), glycerol (20.22%), n-pentadecanoic acid (6.95%), glyceryl monoacetate (6.35 %), ethyl acetimidate (5.39 %) and 3-hydroxy-2,3-dihydromaltol (5.36%) in AEW; β-sitosterol (17.39%), pentadecanoic acid (9.81%), vitamin E (7.82%) and glycerol (7.05%) in MEW; γ-sitosterol (33.45%), vitamin E (10.04%) and campesterol (7.32%) in HEW as major constituents. Maximum phenolics (873 ± 6.01 mgGAE/g dry extract) as well as flavonoids (151 ± 11.44 mgQE/g dry extract) content was found in MEW, which also showed remarkable antioxidant potential (IC₅₀ 6.07 ± 1.4 µg/ml for DPPH and 768 ± 10.4 mg AAE/g dry extract for FRAP assay. In antibacterial activity, maximum inhibition (15 ± 0.9 mm) was observed for HEW against R. solanacearum, followed by AEW against A. tumefaciens and X. phaseoli (11 ± 0.3 mm each). MEW was found positive only against A. tumefaciens. Significant minimum inhibitory concentration (MIC) value observed for AEW against L. monocytogenes (10 mg/ml). Polar extracts had remarkable antioxidant potential, while non-polar extract did show significant antibacterial activity. Further, GC- MS reports indicated that this traditionally useful fern species can be an excellent source of biologically active compounds.     

Pectinolytic enzyme production by Colletotrichum truncatum,causal agent of soybean anthracnose

BackgroundColletotrichum truncatum is the most common pathogenic fungus associated with soybean anthracnose, a prevalent disease in Argentina. Pectinolytic enzymes are involved in the pathogenicity of a wide range of plant pathogenic fungi.ObjectivesTo explore pectinolytic enzyme production in Argentinian Colletotrichum strains isolated from diseased soybean plants from different geographic locations, as a preliminary step to establish the biological role of the pectinolytic enzymes in the Colletotrichum spp.–soybean system, yet unknown.MethodsTen strains were screened for in vitro pectinolytic enzyme production on a defined medium based on pectin as carbon source.ResultsAll isolates were able to grow in this medium and polymethylgalacturonase (PMG), polygalacturonase (PG) and pectin lyase (PL) activities were detected. On the whole, the peak of polygalacturonases activities preceded the day of maximum growth, while PL activity reached its highest level afterwards. Strain BAFC 3097 (from Santa Fe province) yielded high titles of the three enzymes (1.08 U/ml PG, 1.05 U/ml PMG, 156 U/ml PL), after a short incubation period (7–10 days). Low synthesis of polygalacturonases in cultures containing glucose as unique carbon source suggests that these enzymes are constitutive in contrast with PL, which was not detected.ConclusionsThe disparity observed in enzyme production among strains cannot be related to fungal growth, since no major differences in mycelial yield were found; it was not connected with their geographic origin, but might be associated with differences in virulence among strains not yet evaluated.     

Pharmacological properties of biogenically synthesized silver nanoparticles using endophyte Bacillus cereus extract of Berberis lyceum against oxidative stress and pathogenic multidrug-resistant bacteria

The emergence of multidrug resistance in pathogenic bacteria limits the utilization of available antibiotics. The development of alternate options to treat infectious diseases is the need of the day.The present study was aimed to synthesize, characterize and evaluate the bioactive properties of silver nanoparticles. Endophytic bacterium Bacillus cereus (MT193718) isolated from Berberis lycium was used to synthesize biocompatible silver nanoparticles. Antibacterial properties of AgNPs were evaluated against clinically isolated multidrug-resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. AgNPs indicated significant antibacterial activity against S. aureus and K. pneumoniae fwith a zone of inhibition of 17 and 18 mm at a concentration of 1000 µg/ mL with minimum inhibitory concentration of 15.6 and 62.5 µg/mL respectively. Significant antioxidant activity with an IC50 value of 9.5 µg/mL was recorded. Biosynthesized AgNPs were found compatible with red blood cells at a concentration of 31.5 µg/ml with no clumping of erythrocytes. The study suggested that AgNPs synthesized by the endophytic bacterium Bacillus cereus are biologically active and can be used as antioxidant and antibacterial agents against drug-resistant bacteria.     

Antifungal potentiality of mycogenic silver nanoparticles capped with chitosan produced by endophytic Amesia atrobrunnea

This research reports the fabrication of silver nanoparticles (AgNPs) from endophytic fungus, Amesia atrobrunnea isolated from Ziziphus spina-christi (L.). Influencing factors for instance, thermal degree of incubation, media, pH, and silver nitrate (AgNO₃) molarity were optimized. Then, the AgNPs were encapsulated with chitosan (Ch-AgNPs) under microwave heating at 650 W for 90 s. Characterization of nanoparticles was performed via UV–visible (UV–vis) spectrophotometer, Fourier-transform infrared spectrophotometer (FTIR), zeta potential using dynamic-light scattering (DLS), and field-emission-scanning electron microscope (FE-SEM). Anti-fungal activity of Ch-AgNPs at (50, 25, 12.5, 6.25 mg/L) was tested against Fusarium oxysporum, Curvularia lunata, and Aspergillus niger using the mycelial growth inhibition method (MGI). Results indicated that Czapek-dox broth (CDB) with 1 mM AgNO₃, an acidic pH, and a temperature of 25–30 °C were the optimum for AgNPs synthesis. (UV–vis) showed the highest peak at 435 nm, whereas Ch-AgNPs showed one peak for AgNPs at 405 nm and another peak for chitosan at 230 nm. FTIR analysis confirmed that the capping agent chitosan was successfully incorporated and interacted with the AgNPs through amide functionalities. Z-potential was −19.7 mV for AgNPs and 38.9 mV for Ch-AgNPs, which confirmed the significant stability enhancement after capping. FES-SEM showed spherical AgNPs and a reduction in the nanoparticle size to 44.65 nm after capping with chitosan. The highest mycelial growth reduction using fabricated Ch-AgNPs was 93% for C. lunata followed by 77% for A. niger and 66% F. oxysporum at (50 mg/L). Biosynthesis of AgNPs using A. atrobrunnea cell-free extract was successful. Capping with chitosan exhibited antifungal activity against fungal pathogens.     

Rational design,synthesis, anti-HIV-1 RT and antimicrobial activity of novel 3-(6-methoxy-3,4-dihydroquinolin-1(2H)-yl)-1-(piperazin-1-yl)propan-1-one derivatives

In the present study, fifteen novel 3-(6-methoxy-3,4-dihydroquinolin-1(2H)-yl)-1-(piperazin-1-yl)propan-1-one (6a-o) derivatives were designed as inhibitor of HIV-1 RT using ligand based drug design approach and in-silico evaluated for drug-likeness properties. Designed compounds were synthesized, characterized and in-vitro evaluated for RT inhibitory activity against wild HIV-1 RT strain. Among the tested compounds, four compounds (6a, 6b, 6j and 6o) exhibited significant inhibition of HIV-1 RT (IC₅₀ ⩽ 10 μg/ml). All synthesized compounds were also evaluated for anti-HIV-1 activity as well as cytotoxicity on T lymphocytes, in which compounds 6b and 6l exhibited significant anti-HIV activity (EC₅₀ values 4.72 and 5.45 μg/ml respectively) with good safety index.Four compounds (6a, 6b, 6j and 6o) found significantly active against HIV-1 RT in the in-vitro assay were in-silico evaluated against two mutant RT strains as well as one wild strain. Further, titled compounds were evaluated for in-vitro antibacterial (Escherichia coli, Pseudomonas putida, Staphylococcus aureus and Bacillus cereus) and antifungal (Candida albicans and Aspergillus niger) activities.     

Anti-biofilm activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus,Pseudomonas aeruginosa,and Proteus mirabilis

The aim of the present study was to investigate the anti-biofilm activity of biologically synthesized selenium nanoparticles (Se NPs) against the biofilm produced by clinically isolated bacterial strains compared to that of selenium dioxide. Thirty strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were isolated from various specimens of the patients hospitalized in different hospitals (Kerman, Iran). Quantification of the biofilm using microtiter plate assay method introduced 30% of S. aureus, 13% of P. aeruginosa and 17% of P. mirabilis isolates as severely adherent strains. Transmission electron micrograph (TEM) of the purified Se NPs (produced by Bacillus sp. MSh-1) showed individual and spherical nano-structure in the size range of 80–220 nm. Obtained results of the biofilm formation revealed that selenium nanoparticles inhibited the biofilm of S. aureus, P. aeruginosa, and P. mirabilis by 42%, 34.3%, and 53.4%, respectively, compared to that of the non-treated samples. Effect of temperature and pH on the biofilm formation in the presence of Se NPs and SeO₂ was also evaluated.     

Earthworm-mediated synthesis of silver nanoparticles: A potent tool against hepatocellular carcinoma,Plasmodium falciparum parasites and malaria mosquitoes

The development of parasites and pathogens resistant to synthetic drugs highlighted the needing of novel, eco-friendly and effective control approaches. Recently, metal nanoparticles have been proposed as highly effective tools towards cancer cells and Plasmodium parasites. In this study, we synthesized silver nanoparticles (EW–AgNP) using Eudrilus eugeniae earthworms as reducing and stabilizing agents. EW–AgNP showed plasmon resonance reduction in UV–vis spectrophotometry, the functional groups involved in the reduction were studied by FTIR spectroscopy, while particle size and shape was analyzed by FESEM. The effect of EW–AgNP on in vitro HepG2 cell proliferation was measured using MTT assays. Apoptosis assessed by flow cytometry showed diminished endurance of HepG2 cells and cytotoxicity in a dose-dependent manner. EW–AgNP were toxic to Anopheles stephensi larvae and pupae, LC₅₀ were 4.8 ppm (I), 5.8 ppm (II), 6.9 ppm (III), 8.5 ppm (IV), and 15.5 ppm (pupae). The antiplasmodial activity of EW–AgNP was evaluated against CQ-resistant (CQ-r) and CQ-sensitive (CQ-s) strains of Plasmodium falciparum. EW–AgNP IC₅₀ were 49.3 μg/ml (CQ-s) and 55.5 μg/ml (CQ-r), while chloroquine IC₅₀ were 81.5 μg/ml (CQ-s) and 86.5 μg/ml (CQ-r). EW–AgNP showed a valuable antibiotic potential against important pathogenic bacteria and fungi. Concerning non-target effects of EW–AgNP against mosquito natural enemies, the predation efficiency of the mosquitofish Gambusia affinis towards the II and II instar larvae of A. stephensi was 68.50% (II) and 47.00% (III), respectively. In EW–AgNP-contaminated environments, predation was boosted to 89.25% (II) and 70.75% (III), respectively. Overall, this research highlighted the EW–AgNP potential against hepatocellular carcinoma, Plasmodium parasites and mosquito vectors, with little detrimental effects on mosquito natural enemies.     

Antifouling activity exhibited by secondary metabolites of the marine sponge,Haliclona exigua (Kirkpatrick)

Bioassay guided purification of the acetone extract of the marine sponge, Haliclona exigua, (Gulf of Mannar, India) yielded a fraction rich in bis-1-oxaquinolizidine alkaloids, active against seven strains of fouling bacteria as well as cyprids of the cosmopolitan barnacle, Balanus amphitrite. The major alkaloids in the mixture have been tentatively identified as nor-araguspongine C (33.76%), araguspongine C (6.49%), dihydroxy araguspongine (36.36%), methyl and dimethyl derivatives of the latter (12.98 and 10.38%, respectively) from HRMS studies. The lower EC₅₀ (6.6 μg/ml as against the US Navy standard of 25 μg/ml for NPAs) and low toxicity (LC₅₀ 18 μg/ml as compared to 0.00001 μg/ml for TBT) values, coupled with its favourable therapeutic ratio (2.7 as against the requirement of >1) makes these compounds ideal NPAs in environmentally compatible antifouling coatings.     

Expression,purification, phosphorylation and characterization of recombinant human statherin

This work reports the successful recombinant expression of human statherin in Escherichia coli, its purification and in vitro phosphorylation. Human statherin is a 43-residue peptide, secreted by parotid and submandibular glands and phosphorylated on serine 2 and 3. The codon-optimized statherin gene was synthesized and cloned into commercial pTYB11 plasmid to allow expression of statherin as a fusion protein with intein containing a chitin-binding domain. The plasmid was transformed into E. coli strains and cultured in Luria–Bertani medium, which gave productivity of soluble statherin fusion protein of up to 47 mg per liter of cell culture, while 112 mg of fusion protein were in the form of inclusion bodies. No significant refolded target protein was obtained from inclusion bodies. The amount of r-h-statherin purified by RP–HPLC corresponded to 0.6 mg per liter of cell culture. Attenuated total reflection-Fourier transform infrared spectroscopy experiments performed on human statherin isolated from saliva and r-h-statherin assessed the correct folding of the recombinant peptide. Recombinant statherin was transformed into the diphosphorylated biologically active form by in vitro phosphorylation using the Golgi-enriched fraction of pig parotid gland containing the Golgi-casein kinase.     

Evaluation of several tree species for activity against the animal fungal pathogen Aspergillus fumigatus

Aspergillus fumigatus causes severe problems in poultry production systems. Seven South African tree species were selected from the database of the Phytomedicine Programme based on its antifungal activity against the fungus Cryptococcus neoformans. The acetone leaf extracts of the selected species had minimum inhibitory concentrations (MICs) of 0.16 mg/ml and lower in the preliminary screening. The antibacterial and antifungal activities of hexane, dichloromethane, acetone and methanol extracts of the leaves were determined using a two-fold serial microdilution method against a range of commonly encountered animal pathogenic fungi (A. fumigatus, Candida albicans, C. neoformans, Microsporum canis and Sporothrix schenckii) and four nosocomial bacteria (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa). The plant species investigated were Combretum vendae (A.E. van Wyk) (Combretaceae), Commiphora harveyi (Engl.) Engl. (Burseraceae), Khaya anthotheca (Welm.) C.DC (Meliaceae), Kirkia wilmsii Engl. (Kirkiaceae), Loxostylis alata A. Spreng. ex Rchb. (Anacardiaceae), Ochna natalitia (Meisn.) Walp. (Ochnaceae) and Protorhus longifolia (Bernh.) Engl. (Anacardiaceae). All the extracts had activity against at least one of the test organisms over an incubation period of 24 or 48 h. The MIC values of the non-polar and intermediate polarity extracts of O. natalitia, K. anthotheca, C. vendae, C. harveyi, and P. longifolia had MICs as low as 0.08 mg/ml against at least one of the tested bacteria. Furthermore, the acetone extracts of L. alata, K. wilmsii, O. natalitia and C. vendae had antifungal activities with MIC values ranging from 0.04 to 0.08 mg/ml against at least one of the tested fungi. The average MIC values of the plant extracts against the different bacteria ranged from 0.17 to 2.11 mg/ml, while the range was 0.23–1.98 mg/ml for fungi. The Gram-positive bacteria (S. aureus and E. faecalis) were more susceptible to the plant extracts than the Gram-negative bacteria (E. coli and P. aeruginosa). E. faecalis was the most susceptible microbe and C. vendae extracts were the most active against nearly all the bacteria tested. The acetone extract of L. alata was the most active against fungal pathogens, with activity against at least 3 fungal organisms. L. alata was selected for further work to isolate compounds active against A. fumigatus and other fungal pathogens.     

Antitubercular activity of quinolizidinyl/pyrrolizidinylalkyliminophenazines

Novel riminophenazine derivatives, characterized by the presence of the basic and cumbersome quinolizidinylalkyl and pyrrolizidinylethyl moieties, have been synthesized and tested (Rema test) against Mycobacterium tuberculosis H₃₇R_v and H₃₇R_a, and six clinical isolates of Mycobacterium avium and Mycobacterium tuberculosis. Most compounds exhibited potent activity against the tested strains, resulting more active than clofazimine, isoniazid and ethambutol.The best compounds (4, 5, 12 and 13) exhibited a MIC in the range 0.82–0.86 μM against all strains of Mycobacterium tuberculosis and, with the exception of 4 a MIC around 3.3 μM versus M. avium. The corresponding values for clofazimine (CFM) were 1.06 and 4.23 μM, respectively. Cytotoxicity was evaluated against three cell lines and compound 4 displayed a selectivity index (SI) versus the human cell line MT-4 comparable with that of CFM (SI = 5.23 vs 6.4). Toxicity against mammalian Vero 76 cell line was quite lower with SI = 79.     

Novel 3-substituted-1-aryl-5-phenyl-6-anilinopyrazolo[3,4-d]pyrimidin-4-ones: Docking,synthesis and pharmacological evaluation as a potential anti-inflammatory agents

Novel 3-substituted-1-aryl-5-phenyl-6-anilino-pyrazolo[3,4-d]pyrimidin-4-ones of pharmacological significance were synthesized by the reaction of ethyl-(5-amino-3-methylthio-1-aryl-5-phenyl-2H-pyrazole)-4-carboxylates 3a–c with S-methyl diphenyl thiourea independently to produce 1-aryl-3-thiomethyl-5-phenyl-pyrazolo[3,4-d]pyrimidines 4a–c in DMF with catalytic amount of K₂CO₃, which on further treatment with different aromatic amines independently under same reaction conditions generated for compounds 5a–l. The compounds were screened for the anti-inflammatory activity and evaluated for ulcerogenic potential. The compounds 5i exhibited superior anti-inflammatory activity in comparison with diclofenac sodium and comparable activity with celecoxib at a dose of 25 mg/kg. The other compounds 4c, 5c, 5f and 5l were found as active with inhibition of edema in the range of 35–39 after 3 h of administration of test compounds. The ulcerogenic potential of active compounds was observed to be quite lesser as compared to standard. COX-2 docking score of the active compound 5i was found to be better than standard celecoxib.     

Cordyceps cateniannulata,a novel entomopathogenic fungus to control Stenoma impressella Busck (Lepidoptera: Elachistidae) in Colombia

Stenoma impressella is one of the most important defoliator pests in oil palm plantations in Colombia. To identify an alternative method for its control was characterized biologically and molecularly two strains of Cordyceps cateniannulata (CPIsp1201 and IPIsp1201) and three strains of Beauveria bassiana (CPBb0502; CPBb0411; CPBb0404) against S. impressella larvae. Virulence was evaluated under laboratory conditions. In an oil palm leaflet, individual larvae obtained from the insect colony were inoculated with 5 μl of a conidial suspension containing 1 × 10⁷ conidia/ml. The five strains were pathogenic against S. impressella larvae. CPIsp1201 and IPIsp1201 strains resulted in the highest mortality and were subsequently evaluated in two bioassays using a dose of 1 × 10¹³ conidia/ha. In the first bioassay, performed under shaded conditions, leaves of oil palms were infested with 75 larvae from the breeding/treatment. The second bioassay was performed in the field using natural populations. No differences were found between strains in both bioassays and the different dosages (5 × 10¹², 1 × 10¹³, and 1.5 × 10¹³ conidia/ha). Finally, the two strains were evaluated under oil palm plantation conditions at a dose of 1 × 10¹³ conidia/ha in 126 naturally infested palms. Larval mortality caused by the strains IPIsp1201 and CPIsp1201 (79.5% and 70.5%, respectively) was higher than the natural mortality registered in the control (37.3%). Cordyceps cateniannulata used at 1 × 10¹³ conidia/ha was effective at controlling S. impressella.